Television receiving system



GR 52,3%917 y5R Feb. 12, 1946. E KALLMANN l 2,394,917

TELEVISION RECEIVING SYSTEM Filed 0G12. 6. 1943 ma@ S3445 78. lukewarm.

Patented Feb. 12, 1946 UNITED STATES PATENT OFFICE 9 Claims.

My present invention relates to receiving systems for television andother short wave transmitters, and more p-articularly to systems capableof reception of signals from more than one transm1tter.

It is an object of my present invention to provide a receiving systemwhich enables connection of one or several receivers with a plurality ofreceiving antennae.

A further object of my present invention consists in a new multipleantenna arrangement, for example for television receiving systems,permitting of clear and distinct reception of signals from severaltransmitters by one or a plurality of individual receivers.

Still a further object of my present invention consists in a multipleantenna arrangement for television, and other radio receiving systemspermitting distinct and clear reception of the television and soundsignals, transmitted by any one of a number of different television andsound transmitters, by a plurality of individual television and radioreceivers.

Another object of my present invention consists in a new television andradio receiving system which permits use of simplied individualreceivers fed from a common multiple antenna arrangement.

Still another object of my present invention consists in a multipleantenna arrangement combined with amplifying means and other electricaldevices for reception of television and radio transmission from severaldilferent transmitters by a plurality of individual receivers.

With the above objects in View, my present invention mainly consists ofa multiple antenna arrangement for television and other Shortwavereceiving systems comprising a plurality of preferably directionalreceiving antennae, each adjusted to a dilferent transmitter, a commonsignal transmission line associated with all these directional receivingantennae, and one or a plurality of individual television and radioreceivers coupled to and fed by this common transmission line.

An arrangement of this type solves the problem of providing cleartelevision reception in locations where television signals arrive fromdifferent directions. This arrangement avoids the poor signal-to-noiseratio and the multi-path reception typical of all-wave, al1-directionalantennae by provision of a number of directional receiving antennae eachof which might be optimally tuned, directed and located.

It is evident that an arrangement of lthe above type may also be usedfor reception of other radio signals, i. e. that my new multiple antennaarrangement may serve simultaneously for reception of television as wellas other radio signals by a plurality of individual television and radioreceivers.

In order to avoid or at least to minimize interference and interactionbetween the individual receivers during their operation, it ispreferable to provide electrical means, constructed so as to avoid suchinteraction and interference, located between the individual receivers,for example in the common transmission line. It is also of advantage toinsert in this transmission line between the single antennae meansconstructed in such a manner as to minimize interaction between theseantennae.

Each of the antennae might be combined with an amplifying system for thereception of vision and sound signals. I might also provide means forseparating these signals, in combination with each of the antennae. Thethus obtained separated sound signals might be further amplified andthen modulated upon a new carrier, this new carrier being furtherremoved from that of the vision carrier, so as to simplify theseparation of these two signals in the individual television receivers.For reception of frequency modulated signals, I might also incorporateso-called discriminator circuits into the amplifiers associated witheach of the antennae and thereby transform the frequency modulation ofthe signals into amplitude modulation.

The novel features which I consider characteristic of my invention areset forth in particular in the appended claims. The invention itself,

however, both as to its construction and its meth-A od of operation,together with additional objects and advantages thereof, will be bestunderstood from the following description of specific embodiments, whenread in connection with the accompanying drawing in which:

Fig. 1 shows the general arrangement of my new television and radioreceiving system; and

Fig. 2 shows the detailed arrangement of one antenna arrangement and onetelevision receiver in detail.

As shown in Figure 1, my new receiving system consists of a plurality ofpreferably directional television and radio receiving antennae I 0, I Iand I2 adjusted and tuned to several dilerent transmitters, the commontransmission line I3 connected with the antennae I0, Il and I2 byconductors I4, I5 and I6, and a plurality of individual receivers I'I,I8 and I9 coupled also to the common transmission line i3 by means ofconductors 20, 2| and 22. Each of these receivers may be provided withtelevision reproducing means 23, e. g. a cathode ray tube, and soundreproducing means 24, e. g. a loud speaker of usual type.

The signal level to be maintained in the trans` mission system dependson the type and sensitivity of the receivers connected to it. In case ofrelatively strong incoming signals and ordinary type, fully sensitivereceivers the output of the antennae may be directly combined bysuitable passive networks matched to the impedance of the transmissionsystem. Whenever the resulting signal energy level is inadequate, abooster amplifier near the antenna end of the transmission system isdesirable.

In accordance with a preferred embodiment of my present invention, Ipropose to assign a separate amplifier channel to each antenna and tofeed theirs'eombined output to the common transmission line either byparalleling all the output electrodes of the amplifiers or by separatingtheir capacities in a well-known manner in a matched network. Such anetwork may be a simple lowpass filter with a cut-off above the highestreceived frequency, or an m-derived low-pass filter adapted toaccommodate larger capacities with a given matching impedance; thenetwork may also be a band-pass filter system passing all desiredfrequencies and accommodating the output electrode capacities as thecapacities of the shunt circuits, or an m-derived band-pass filter. Oneend of these filter systems may either be terminated with a matchingresistance or be matched to another branch of the transmission system.

It is understood that in this case all signals remain on their originalcarriers and on a relatively low signal level. Thus, the individualreceivers I'l, I8 and I9 coupled to and fed by the common transmissionline I3 may be of the ordinary type. In the case of strong receivedsignals, the antennae may be connected directly to the transmission lineI3 and only in some instances may it be necessary to provide at theantenna end of the transmission line booster amplifiers which may serveto obtain an adequate and regulated energy level yet leave carrierfrequencies and type of modulation unchanged.

In the case that simplied individual receivers are used, the entirereceiving system is modif-led in accordance with another embodiment ofmy present invention. Such an integrated receiving system is shown inFig. 2 and will now be described in detail.

This integrated receiving system may consist, as shown in Fig. 2, of aplurality of antennae 25, one of which is shown in the figure, acombined signal amplifying and separating system 26 interposed betweeneach of the antennae and the common transmission line I3, and filteringand selecting systems 21 interposed between each of the simplifiedvision and sound signal receivers 28, 29 and the transmission line I3. iAs shown in Fig. 2, I connect the antenna 25 with' a combined vision andsound signal amplifier 30 providing both vision and sound signals oncarriers of relatively high energy level. Automatic volume control meansfor keeping this relatively high energy level constant are forming partof this amplifier 30. This amplifier 30 is connected on the one handwith a vision signal amplifier incorporating sound signal suppressingmeans 3| and on the other h'and with a combined vision signal suppressorand sound signal amplifier 32. After detection and furtheramplification, the sound signals may either be directly fed into thetransmission line I3 or may serve to modulate a local carrier oscillator33. In this way, it is possible to shift the sound signals from acarrier of relatively high frequency onto a carrier of relatively lowfrequency and yet to choose for each sound channel a separate carrierfrequency differing from the frequencies of all other sound andtelevision channels used in the area in which the new television andsound receiving system is located.

For reception of frequency modulated sound signals, I may combine, asshown in Fig. 2, socalled limiting means 34 with the sound signalamplifier 32 for stripping the frequency modulated sound signals of anyamplitude modulations which are usually caused by undesired noise. Theselimiting means are followed by a so-called frequency modulationdiscriminator 35 transforming carrier frequency variations into audiofrequency currents corresponding to the transmitted sound signals. Thesein turn serve to modulate a local carrier oscillator 33, having adifferent carrier frequency for each program received.

The modulated oscillator 33 0n the one hand and the vision signalamplifier 3| on the other hand are connected by conductors 36 and 31respectively to transmission line I3. Means for preventing interactionbetween th'em, e. g. an ultra short wave choke 38 adapted to preventvision ultra short waves to enter the sound carrier oscillator 33 may beprovided in the conductors 36.

Each of the filtering and selecting systems comprises vision signalfiltering means 40 and sound signal filtering means 4I connected in theway shown in the drawing with transmission line I3 by a buffer tube 39.The vision and sound signals are filtered by the vision signal filteringmeans 40 and th'e sound signal filtering means 4I. Ganged selectorswitches 42, 43 and 44 for selecting one of the Vision and soundchannels, i. e. for adjusting the receiver to one of the pairs ofsignals from the antennae Ill, II or l2, are provided before and afterthe filtering means 40 and 4I. The vision signal channel 28 comprisesdetecting and amplifying means and the cathode ray tube for reproducingthe received vision signals in the customary way. The sound signalchannel 29 also comprises detecting and amplifying means and feeds aloud speaker for reproducing the sound signals in the usual way.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofsignal reception system differing from the types described above.

While I have illustrated and described the invention as embodied intelevision receivers, comprising vision and sound channels, I do notintend to be limited to the details shown, since various modificationsand structural changes may be made without departing in any way from thespirit of my invention.

Without further analysis, the foregoing will so fully reveal the gist ofmy invention that others can, by applying current knowledge, readilyadapt it for various applications without omitting features that, fromthe standpoint of prior art, fairly constitute essential characteristicsof the generic or specific aspects of this invention and, therefore,such adaptations should and are intended to be comprehended within themeaning and range of equivalence of the following claims.

What I claim as new and desire to secure by Letters Patent is:

1. Multiple antenna arrangement for television receiving systemscomprising a series of directional television receiving antennae eachadjusted to a different television transmitter, a common televisiontransmission line associated with all said directional televisionreceiving antennae, a plurality of individual television receiverscoupled to and fed by said common tele- Vision transmission line, andelectrical means interposed between any two of said receivers andconstructed in such a manner as to minimize interaction and interferencebetween said receivers during operation of the same.

2. Multiple antenna arrangement for television receiving systemscomprising a series of directional short wave receiving antennae eachadjusted to a different short wave transmitter, a common transmissionline associated with all said directional short wave receiving antennae,a plurality of individual television receivers coupled to and fed bysaid common television transmission line, and electrical meansinterposed between said antennae and constructed in such a manner as tominimize interaction and interference between them.

3. Multiple antenna arrangement for television and radio receivingsystems, comprising a series of directionally selective television andradio receiving antennae each directionally adjusted to a differenttelevision and radio transmitter, a series of combined vision and soundsignal amplifying systems connected each to one of said directionallyselective antennae adapted to separate the sound signals from the visionsignals, a common transmission line, a series of electrical couplingsfeeding each of said separated sound signals to said common transmisionline, a series of other electrical couplings feeding each of said visionsignals to said common transmission line, and a plurality of individualtelevision and radio receivers coupled to and fed by said commontransmission line.

4. Multiple antenna arrangement for television and radio receivingsystems comprising a series of directionally selective television andradio receiving antennae each directionally ad- J'usted to a differenttelevision and radio transmitter, a series of combined vision and soundsignal amplifying systems connected each to one of said directionallyselective antennae adapted to separate the sound signals from the visionsignals, a series of oscillators modulated with said separated soundsignals, a common transmision line, mean electrically connecting each ofsaid amplifying systems with said common transmission line, meanselectrically connecting each of said modulated oscillators with saidcommon transmission line, and a plurality of individual television andradio receivers coupled to and fed by said common transmission line.

5. Multiple antenna arrangement for television and radio receivingsystems comprising a series of directionally selective television andradio receiving antennae each directionally adjusted to a differenttelevision and radio transmitter, a series of combined vision and soundsignal amplifying systems connected each to one of said directionallyselective antennae, a series of Vision signal supressing means connectedeach with one of said combined vision and sound amplifying systems, aseries of sound signal amplifying and frequency transforming meansconnected each with one of said visiion signal suppressing means foramplifying the sound signals separated by said vision signal suppressingmeans and reducing the frequencies of said sound sisnals, a commontransmission line, means electrically connecting each of said soundsignal suppressing means with said common transmission line, meanselectrically connecting each of said amplifying and frequencytransforming means with said common transmission line, and a pluralityof individual television and radio receivers coupled to and fed by saidcommon transmission line.

6. Multiple antenna arrangement for television and radio receivingsystems comprising a series of directional television and radioreceiving antennae adjusted to several different television andfrequency modulation radio transmitters, a series of vision and soundsignal amplifying systems connected each to one of said antennae, aseries -of discriminating means for transforming the frequencymodulations of said sound signals into amplitude modulations, a seriesof frequency transforming means connected each with one of saiddiscriminating means for reducing the frequencies of said amplitudemodulated sound signals obtained by said discriminating means, a seriesof sound Signal suppressing means connected each with one of said visionsignal amplifying systems, a common transmission line, a series ofelectrical connections feeding said sound signals into said commontransmission line, a series of electrical connections feeding saidvision signals into said common transmission line, and a plurality ofindividual teleVisi-on and amplitude modulation radio receivers coupledto and fed by said common transmission line.

7. Multiple antenna arrangement for television and radio receivingsystems comprising a series of directional television and radioreceiving antennae adjusted to several different television and radiotransmitters, a series of combined vision and sound signal amplifyingsystems connected each to one of said antennae, a series of visionsignal suppressing means connected each with one of said combined visionand sound amplifying systems, a series of sound signal amplifying meansconnected each with one of said vision signal suppressing means foramplifying the sound signals separated by said vision signal suppressingmeans, a series of oscillating systems, a series of modulators fed eachfrom one of said sound signal amplifying means and modulating saidoscillating systems, a common transmission line, means electricallyconnecting each of said oscillating systems with said commontransmission line, means electrically connecting each of said combinedvision and sound signal amplifying means with said common transmissionline, and a plurality of individual television and radio receiverscoupled to and fed by said common transmission line.

8. Multiple antenna arrangement for television and radio receivingsystems comprising a series of directional television and radioreceiving antennae adjusted to several diierent television and radiotransmitters, means for separating the transmitted Vision and soundsignals, a common transmission line associated with said separatedmeans, and a plurality of individual television and radio receiverscoupled to and fed by said common transmission line, each of saidindividual receivers including separate vision and sound signal filtersfor said separated vision and sound signals, vision and sound signalamplifiers, selector switches connecting said vision and sound signalfilters with said vision and sound signal ampliiersfor adjusting saidvision and sound signal filters to the various television and radiotransmissions, and television and sound reproducing means connected tosaid vision and sound signal amplifiers respectively.

9. Multiple antenna arrangement for television and radio receivingsystems comprising a series of directional television and radioreceiving antennae adjusted to several different television andfrequencymodulation radio transmitters, a series of combined vision and soundsignal amplifying systems comprising means for separating thetransmitted Vision and sound sigtrically connecting each of saidamplifying systems With said common transmission line, and a pluralityof individual television and amplitude modulation radio receiverscoupled to and fed by said common transmission line, each of saidindividual receivers including Vision and sound signal lters for saidseparated vision and sound signals, vision and sound signal amplifiers,selector switches connecting said vision and sound signal lters withsaid vision and sound signal amplifiers for adjusting said vision andsound signal filters to the various television and radio transmissions,and television and sound reproducing means connected to said vision andsound nais, connected each to one of said antennae, a 15 signalamplifiers respectively.

common transmission line, a series of means elec- HEINZ E. KALLMANN

